1gq0: Difference between revisions
New page: left|200px<br /><applet load="1gq0" size="450" color="white" frame="true" align="right" spinBox="true" caption="1gq0" /> '''SOLUTION STRUCTURE OF ANTIAMOEBIN I, A MEMBR... |
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'''SOLUTION STRUCTURE OF ANTIAMOEBIN I, A MEMBRANE CHANNEL-FORMING POLYPEPTIDE; NMR, 20 STRUCTURES'''<br /> | '''SOLUTION STRUCTURE OF ANTIAMOEBIN I, A MEMBRANE CHANNEL-FORMING POLYPEPTIDE; NMR, 20 STRUCTURES'''<br /> | ||
==Overview== | ==Overview== | ||
Antiamoebin I is a membrane-active peptaibol produced by fungi of the | Antiamoebin I is a membrane-active peptaibol produced by fungi of the species Emericellopsis which is capable of forming ion channels in membranes. Previous structure determinations by x-ray crystallography have shown the molecule is mostly helical, with a deep bend in the center of the polypeptide, and that the backbone structure is independent of the solvent used for crystallization. In this study, the solution structure of antiamoebin was determined by NMR spectroscopy in methanol, a solvent from which one of the crystal structures was determined. The ensemble of structures produced exhibit a right-handed helical C terminus and a left-handed helical conformation toward the N-terminus, in contrast to the completely right-handed helices found in the crystal structures. The NMR results also suggest that a "hinge" region exists, which gives flexibility to the polypeptide in the central region, and which could have functional implications for the membrane insertion process. A model for the membrane insertion and assembly process is proposed based on the antiamoebin solution and crystal structures, and is contrasted with the assembly and insertion mechanism proposed for other ion channel-forming polypeptides. | ||
==About this Structure== | ==About this Structure== | ||
1GQ0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Emericellopsis_sp. Emericellopsis sp.] with ACE as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | 1GQ0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Emericellopsis_sp. Emericellopsis sp.] with <scene name='pdbligand=ACE:'>ACE</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GQ0 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Emericellopsis sp.]] | [[Category: Emericellopsis sp.]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Driscoll, P | [[Category: Driscoll, P C.]] | ||
[[Category: Galbraith, T | [[Category: Galbraith, T P.]] | ||
[[Category: Harris, R.]] | [[Category: Harris, R.]] | ||
[[Category: Wallace, B | [[Category: Wallace, B A.]] | ||
[[Category: ACE]] | [[Category: ACE]] | ||
[[Category: antibiotic]] | [[Category: antibiotic]] | ||
| Line 23: | Line 23: | ||
[[Category: peptaibol]] | [[Category: peptaibol]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:52:45 2008'' | ||
Revision as of 13:52, 21 February 2008
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SOLUTION STRUCTURE OF ANTIAMOEBIN I, A MEMBRANE CHANNEL-FORMING POLYPEPTIDE; NMR, 20 STRUCTURES
OverviewOverview
Antiamoebin I is a membrane-active peptaibol produced by fungi of the species Emericellopsis which is capable of forming ion channels in membranes. Previous structure determinations by x-ray crystallography have shown the molecule is mostly helical, with a deep bend in the center of the polypeptide, and that the backbone structure is independent of the solvent used for crystallization. In this study, the solution structure of antiamoebin was determined by NMR spectroscopy in methanol, a solvent from which one of the crystal structures was determined. The ensemble of structures produced exhibit a right-handed helical C terminus and a left-handed helical conformation toward the N-terminus, in contrast to the completely right-handed helices found in the crystal structures. The NMR results also suggest that a "hinge" region exists, which gives flexibility to the polypeptide in the central region, and which could have functional implications for the membrane insertion process. A model for the membrane insertion and assembly process is proposed based on the antiamoebin solution and crystal structures, and is contrasted with the assembly and insertion mechanism proposed for other ion channel-forming polypeptides.
About this StructureAbout this Structure
1GQ0 is a Single protein structure of sequence from Emericellopsis sp. with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Solution NMR studies of antiamoebin, a membrane channel-forming polypeptide., Galbraith TP, Harris R, Driscoll PC, Wallace BA, Biophys J. 2003 Jan;84(1):185-94. PMID:12524274
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